1. Field of the Invention
The present invention relates to a front window formed in a front face of a cabin of a construction machine such as a hydraulic shovel.
2. Description of the Background Art
The background art of the invention will be explained by describing a cabin 1 of a hydraulic shovel shown in FIG. 4, as an example.
The cabin 1, which is adapted to accommodate various operation devices therein, includes a door 2 disposed on the left side of the operation devices and a front window 3 disposed on the front side of the cabin 1. The front window 3 includes an upper window 4 capable of being opened/closed, e.g. capable of vertically sliding, and a lower window 5 disposed below the upper window 4 to make contact with the upper window 4. The upper window 4 has an unillustrated window frame, and a glass plate 6 adhered to an outer face of the window frame. Similarly to the upper window 4, the lower window 5 has a window frame and a glass plate 7. The glass plate 6 of the upper window 4 and the glass plate 7 of the lower window 5 have respective ends which make contact with each other, between which ends a shock-absorbing trim 8 is provided.
FIG. 5 and FIG. 6 show a conventional example of a structure of the thus mutually contacting ends of the upper window 4 and the lower window 5 in the front window 3.
The window frame of the upper window 4 has an underside portion 9, to which a reinforcing plate 11 and a lower handle 12 for opening and closing the upper window 4 are attached. The underside portion 9 is formed of a base wall 9a disposed in an upright posture along the glass plate 6, and a bulging wall 9b extending from a lower end of the base wall 9a, obliquely upward, toward the inner side of the cabin, i.e., toward the right side in FIG. 5 and FIG. 6, thus having a V-shaped cross section. The base wall 9a has an outer surface, to which the glass plate 6 is attached via a block-shaped shock-absorbing rubber member 10. The reinforcing plate 11 is attached to an upper face of the bulging wall 9b. Specifically, the reinforcing plate 11 has an oblique portion fixed to the upper face of the bulging wall 9b along the upper face thereof and an upper portion extending upward from the upper end of the oblique portion.
The structure shown in FIG. 5 and FIG. 6 is not described in a printed publication. Meanwhile, there exist some documents describing the related art of the invention Japanese: Unexamined Patent Publication No. 2004-27700 and Japanese Unexamined Utility Model Publication No. Hei 6-42328.
The underside portion 9 of the window frame of the upper window 4 shown in FIG. 5 and FIG. 6 is continuous with an inner face of the glass plate 6 of the upper window 4 through the shock-absorbing rubber member 10 in a step form. This form intends to allow water condensed into dew (described “condensed water” below) W on the inner face of the glass plate 6 due to a temperature difference between the inside and the outside of the cabin to arrive at the underside portion 9 to build up thereon through moving on the glass plate 6 and the shock-absorbing rubber member 10; the build up of the condensed water may rust the underside portion 9 (particularly, an upper end face of the base wall 9a).